In multicast and broadcast applications, data are transmitted from a server to multiple receivers over wired and/or wireless networks. A multicast system as used herein is a system in which a server transmits the same data to multiple receivers simultaneously, where the receivers form a subset of all the receivers up to and including all of the receivers. A broadcast system is a system in which a server transmits the same data to all of the receivers simultaneously. That is, a multicast system by definition can include a broadcast system.
In server type devices, Ethernet traffic to and from certain devices (identified by MAC address) must be inspected. Packets destined to vendor devices must have IEEE 802.1Q/p headers added to them, packets from vendor devices to non-vendor device must have any IEEE 802.1Q/p headers removed. Since the hardware in the switch processor cannot fulfill those requirements, this packet inspection/modification must be done in software. Operating the switch ports in software mode has an impact on performance, decreasing bandwidth throughput.
In the past, it would be common practice to assign certain ports on the router/switch to be dedicated for the different purposes (e.g., certain ports are full speed and certain other ports have packet inspection/tagging). The disadvantage of this is that if the end-user has more devices than ports available, then the end-user requires extra equipment (e.g., switches).